1. Expression of CCAAT/Enhancer Binding Proteins during Porcine Preadipocyte Differentiation
- Author
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Z.K. Yu and G.J. Hausman
- Subjects
Cytotoxicity, Immunologic ,Time Factors ,Stromal cell ,Swine ,Cellular differentiation ,Blotting, Western ,Cell Count ,Biology ,Dexamethasone ,Western blot ,Adipocytes ,Image Processing, Computer-Assisted ,medicine ,Animals ,Insulin ,Protein Isoforms ,Cells, Cultured ,Cell Nucleus ,Ccaat-enhancer-binding proteins ,medicine.diagnostic_test ,Antibodies, Monoclonal ,Nuclear Proteins ,Cell Differentiation ,Cell Biology ,Lipid Metabolism ,Immunohistochemistry ,Molecular biology ,DNA-Binding Proteins ,Blot ,Adipogenesis ,Cell culture ,Antigens, Surface ,CCAAT-Enhancer-Binding Proteins ,Stromal Cells ,Biomarkers ,Fetal bovine serum - Abstract
The expression of three CCAAT/enhancer-binding proteins (C/EBPs) was examined with immunocytochemistry and Western blot analysis during preadipocyte differentiation in porcine stromal vascular (S-V) cell cultures. Regardless of treatment and time in culture, immunoreactivity for all three C/EBP isoforms was restricted to cell nuclei. At day 1, 50 +/- 6% of S-V cells were C/EBPdelta positive, whereas 13 +/- 3 and 11.7 +/- 3% of S-V cells were AD-3 and C/EBPalpha positive, respectively. After 3 days of seeding in fetal bovine serum (FBS) and dexamethasone (DEX), C/EBPdelta; AD-3, and C/EBPalpha-positive cells increased to 67 +/- 5, 42 +/- 4, and 32 +/- 3%, respectively. Double staining clearly showed that most of the C/EBPalpha reactive cells had not accumulated appreciable lipid after 3 days of FBS + DEX. Following 3 days of insulin treatment, the percentage of C/EBPdelta cells was 50 +/- 6, whereas the percentage of AD-3- and C/EBPalpha-positive cells was 41 +/- 4 and 31 +/- 3, respectively. After insulin treatment all fat cells were AD-3, C/EBPalpha, and C/EBPdelta positive. Double staining demonstrated that fat cells were C/EBPdelta reactive throughout the culture period. Western blotting showed changes in C/EBP isoform expression that were consistent with the immunocytochemical results. We conclude that C/EBPalpha is a terminal differentiation marker which is expressed later than AD-3 but further studies are needed to determine the relationship between C/EBPdelta and adipogenesis in porcine S-V cultures.
- Published
- 1998